Commentary

Hey, look at me! I'm establishing a thing in advance! Sort of. We now know with certainty that Tedd has a belt. Of course, we can clearly see he has a belt, but now we know it can return people to being human! For reasons! It's a pretty fancy belt.

There is an explanation for why Elliot is bisexual in a female form beyond "well, he's a girl now, so..." that will be addressed much, much later on. A fair point that has been brought up by people in the past is that there's no reason changing sexes should make someone attracted to different people than before by default.

Of course, who knows what would really happen if you had a ray gun that could just suddenly do that. All sorts of things about a person could change after that dramatic and complete a biological shift. For all we know, they'd suddenly like different foods or something. That said, we can't really test it without access to some manner of ray gun that can transform people like that, so it's gonna be difficult to confirm anything one way or the other.